Process of manufacturing filtering material.



FRITZ POTT, OF FBIEDEN'AU, NEAR B E RLIN, GERMANY.

No Drawing.

Specification of Letters Patent.

Application filed August 16, 1913. Serial No. 785,174.

PROCESS OF MANUFACTURING FILTEBING- MATERIAL.

Patented Mar. 3, 1914.

tage as compared with these substances that its action and form can be predetermined as desired.

To this end I impregnate a porous mineral substance with peptonic albuminoids,' and then dry the porous mineral product. I'then str igly calcine the resulting substance,

'- while simultaneously excluding the air therefrom, so that only carbon and certain salts remain. These salts are then washed outwith water or in some cases with acids,

while the carbon remainsfirmly adherent to the mineral substance.'= ""The filtering material produced in this manner can-be employed for cleaning or purifying a very large variety of liquids, e. g. for removing the coloring substances and salts from liquids of all kinds. As examples of the purposes of employment may be mentioned, cleaning juices, refining oils and purifying water.

The purifying action of the new filtering material is based on the following considerations. The extremely finely distributed carbon has quite as high, a surface action as that due to the carbon obtained either from the glue-yielding substances in bones or from the blood, which latter carbon is extensively employed in practice as is well-known. The peptonic condition of the albuminous solution enables the liquid to penetrate into the minutest pores of the starting material, so that the active carbon is uniformly distributed and very effective throughout the re sulting product. Moreover my new filtering material can be regenerated in the same way as bone-charcoal.

The filtering material I obtain has very special advantages when it is employed for purifying water. 7

As is well-known, when removing iron and hardness from water a certain time must be allowed before precipitated matter can be.

c, I I r 7 separated out. It is also well-known that by allowing the particular reactions to take place in the presence of previously formed deposits of a similar or at least nearly related kind,'the operation can be accelerated by so-called cont-act action. In practice it is the filtering material that is almost exclusively the carrier of the deposits which act in this manner. This can be very well observed in the gravel-filter; Namely, when a gravel-filter is new or thoroughly washed with water While simultaneously stirred, so that there is no iron deposit present, the power of the filter to remove iron is not approximately equal to that of a filter of thiskind which had become charged with deposit and which had been some time at work. The gravel-filter must, however, be thoroughly washed from time to time, because it would otherwise becomechoked and allow too little water to pass through. Plants for removing iron by gravel filtrationare therefore subject to continual variation in re spect to their qualitative output. Even when the smooth gravel is replaced by a more porous material of an inorganic nature with a view to encouraging the formation in the pores of a firmly adherent layer of deposit, the conditions are practically unimproved, for in this case also th'efine particles are much too readily washed out. of the pores for the variable action already described with reference to the gravel-filter to be eliminated.

When organic material, e. g. wood-wool, is-employed the action is difierent. In this case the deposited particles which are in direct contact with the fibers adhere so firmly that they cannot be dislodged when the filter is washed. Consequently, it is only when the filter is newly filled with wood-wool that p e. g. schizomycetes. -The better the e ect in abstracting the iron, the more serious does the hygienic defect becomef According to myinrention I obviate the above defects, and thus not only make an important industrial advance, but also provide a process of treating a material of inorganic ori in in such manner that the finest deposits ad ere to and in itso firmly that,

-means of a 15% alkali solution, then impregnating suitable stones, bricks or the like with this solution, dryin the impregnated stones, thereupon strong y calcining them while excludin the air, and finally washingout the salts. he stones or bricks preliminarily prepared in thismanner act in the manner described as organic substances,-i. e. even when carefully washed they contain so much catalytically' acting. deposit in themselves that the filter made from them works uniforml and, .in respect to v qualitative results, satlsfactorily.

In order toobtain the desired action uniformly from the beginning I may deposit metallic hydroxid' and calcium carbonate in the stonesby impregnating them in known manner with severa reagents whichso act on one another as to form a deposit.

- Example: Granulted porous bricks are first impregnated with a 5%, aqueous peptonic solution produced by means of alkahs,

then dried, calcined, washed in a' suitable vessel, and then impregnated with solutions of the'salts of iron, aluminium, manganesenickel, cobalt. By means of lime. water, to

which gypsum has been added, the hydroxrial, consisting in impregnating a mineral substance with a solution 0 albuminoids, in drying the same, in thereupon 'highly heating the same .while excluding. the

! stance with a employing a soluble carbonate, calcium carbonate is precipitated from the gypsum.

According to known processes for chargmg inorganic filtering materials with carbon, these materials have either been treated with gaseous heavy hydrocarbons under the action of heat with the object of forming soot, or they have been intimately mixed with fine pulverized brown coal or lignite and then calcined. In my process, however, by impregnating the filtering material with a carboniferous liquid and heating the same, I obtain not only a very adherent precipitate of very active animal charcoal, but also a very fine and regular distribution such as is not obtainable by the known processes.

I claim v I 1. A process of making a filtering material, consisting in impregnating a porous mineral substance with a solution of albuminoids, inv drying the same, inthereupon highly heating the same while excluding the air therefrom, and in washin the same, and

the treate mineral subeposit of an hydroxid of a in 'then loadin stance with a metal mixed with. calcium carbonate,

2. A process of maln'ng a filtering mateorous 'air therefrom, and in washin the same, and in then loadin the treateg mineral subeposit of iron mixed with calcium carbonate.

In testimony whereof, I afiix my signature inthe presence of two witnesses FRITZ POTT.

Witnesses; I

HENRY HASPER, ARTHUR Somzomma. 

